Noxafil (Posaconazole)

• Posaconazole is a triazole antifungal indicated for serious fungal infections and prophylaxis in high‑risk patients.
• Invasive aspergillosis: effective treatment to eradicate Aspergillus species in immunocompromised individuals.
• Invasive candidiasis: clears systemic Candida infections resistant to other azoles.
• Prevention of fungal infections in immunocompromised patients: provides prophylactic coverage during chemotherapy, stem‑cell transplantation or prolonged neutropenia.

• Posaconazole inhibits the fungal enzyme lanosterol 14α‑demethylase, a cytochrome P450‑dependent protein essential for converting lanosterol to ergosterol. By blocking ergosterol synthesis, the drug disrupts fungal cell membrane formation, leading to increased membrane permeability and inhibition of fungal growth.

Posaconazole may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Nausea or vomiting
• Diarrhea or abdominal discomfort
• Headache
• Elevated liver enzymes (ALT, AST)
• Rash or pruritus
• Fatigue

Serious or Rare Side Effects

• Hepatic failure or severe hepatitis
• QT interval prolongation leading to arrhythmia
• Severe allergic reactions such as Stevens‑Johnson syndrome
• Acute pancreatitis
• Visual disturbances

• Posaconazole requires careful monitoring and specific precautions before and during therapy.
• Monitor liver function: perform baseline and periodic hepatic enzyme tests.
• Assess cardiac risk: obtain ECG in patients with known QT prolongation or electrolyte disturbances.
• Avoid use in patients with known hypersensitivity to posaconazole or other triazoles.
• Dose adjustment may be needed in severe hepatic impairment.
• Avoid concomitant use with other QT‑prolonging agents when possible.
• Store at room temperature below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Posaconazole interacts with several medications; awareness of interaction severity guides clinical decisions.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine, phenytoin, St. John’s wort) – may markedly reduce posaconazole exposure.
• Concurrent QT‑prolonging drugs (e.g., quinidine, sotalol) – increase risk of arrhythmia.

Moderate Interactions (Monitor Closely)

• Warfarin – may enhance anticoagulant effect, monitor INR.
• Digoxin – potential increase in serum levels, check concentrations.
• Statins metabolized by CYP3A4 (e.g., simvastatin) – monitor for myopathy.
• Oral contraceptives – efficacy may be reduced, consider alternative contraception.
• HIV protease inhibitors – may increase posaconazole levels, observe for toxicity.